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(No Model.)

G. W. LORD.

MECHANICAL TELEPHONE.

N0.'3'59.217. Patented Mar. 8, 1887. .I

WPIESSEE.

I eUNITED STATES IParenti? Ormea,

GEORGE W. LORD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE LORD ACOUSTIC TELEPHONE MANUFACTURING COMPANY, OF SAME PLACE.

MECHANICAL TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 359,217, dated March 8, 1887.

Application liled October 20, 1856. Serial No. 216,704. (No model.)

- TOaZZ whom it may concern:

Be it known that I, GEORGE W. LORD, a citizen ofthe United States, and a resident of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Mechanical Telephones, of which the following is a specitication.

rIhis invention is an improvement upon the mechanical telephone described in my applixg cation, No. 2l4,622,'for Letters Patent of the United States.

The said invention consists, iirst, in the combination of a diaphragm with a telephonecase consisting of two sections having said 1 diaphragm between them, said sections being constructed with bell-shaped cavities which ilare at their edges to allow the diaphragm to occupy the entire area in crosssection of the case; secondly, in a telephone-case consisting zo of two sections having the diaphragm between them, and having also elongated cavities in combination with said diaphragm,aud a mouthpiece which is inserted in the side of one of said sections above the bottom of its cavity; thirdly, in the combination of a ring, to which thediaphragm'isatt-ached,with said diaphragm and said sections, the inner face of the ring being beveled to constitute a continuation of the inner vface of one of said sections.

In theaccompanying drawings, Figure l is a view, in longitudinal section, of my improved telephone. Fig. 2 is a view, in elevation, of the same; and Fig. 3 is a detached sectional view showing the call. 5 In these several iigures the same letters refer to the same parts.

Referring to the drawings, A is the telephone, which is substantially the same as that described in the application before referred 4c Jto-that is, it consists of a hollow case, of wood or other suitable material, made in two parts and united together, surrounded by a band of lead or some other suitable uonresonant substance, and divided by a diaphragm, C, of any 4 5 material suitable for use in a mechanical telephone. The walls of this case form two bellshaped cavities on each side of the diaphragm, and these cavities are elongated, as shown. The daring mouths of these cavities allow the 5o diaphragm to be as large as the area of the cross-section of the telephonecase.

B is the conducting-wire, which is attached to the diaphragm by the knob g, as shown. The exterior of this case may have any desired form; but for simplicity and cheapness of construction the cylindrical form shown is preferable. The section b is provided with an opening, D, in its side just above the bottom, which receives the mouth-piece. The lower part, b, of the case may also have attached 6o thereto a flexible tube, E, having an ear or month piece attached thereto, which tube may also be used for transmitting and receiving the voice, or both the opening in the side and the flexible tube may be used. This tube and earpiece are preferably of the form' and material used in stethoscopes and instruments for the use of the deaf. The tube is inserted in the bottom of the case below the diaphragm, and terminates within the case ina trumpet-shaped piece, F, of wood, hard rubber, or other suitable material, which extends within the case about half-way to the diaphragm. By the use of this truinpetshaped attachment I lind that the transmission of sound is much facilitated. 7 5

The diaphragm is stretched over and suitably secured to a wooden ring, d, which is inserted into a recess in the section c, and bears against a shoulder on the same. In order that the diaphragm` may extend entirely over the 83 cavity in the section b ofthe case A, and thus operate with itsy full effect, thc inside of this ring is beveled oft'.

A suitable calling device is desirable for use with a mechanical telephone. Fig. 3 rcpre- 85 sents one which I have devised. It consists of a thin plate, f, pivoted in a slot in the side of the section b of the case and proj ecting from the same, as shown at z'. To this plate is attached au arm, e,which terminates in a knob, go II, under the end of the conducting-wire. The weight of this arm keeps the knob H from contact with the end of the wire; but by means of the projection i it can be struck against the end of the wire with suflicient force to produce 9 5 a loud call in the telephone at the other end of the line.

Having thusdescribed my invention,what I claim, and desire to secure by Letters Patent of the United States, is Y l. In combination with the diaphragm of a mechanical telephone, a telephone-caso consisting of two sections having said diaphragm between them, said Sect-ions being constructed with bell-shaped cavities which Hare at their 3. The beveled ring d and the diaphragm attached thereto, in combination with the two 15 sections ofthe telephone-case, the inner face of edges from their interior surface to their eX- I said ring forming a continuation of the inner 5 yterior, to allow the diaphragm to occupy the face of one of said sections and completing the entire area in erosseection of the case. l outward flare thereof.

2. In combination with a diaphragm, a tele- In witness whereof I have hereunto set my 2o phonecase Consisting of two sections having,` name in the presence of two Sul'iscribing witthe diaphragm between them, and having also nesses.

1o cavities elongated in longitudinal section, and a mouth-piece which is inserted in the side of one of said sections above the bottom of its l cavity7 substantially as set forth. i

GEORGE YV. LORD.

VitneSSeS: A

THOMAS F. WELLS, JOHN Il. CooMuS. 

